The present invention relates to fabrics prepared from spun yarns and having high stretchability and excellent in recovery from elongation, and to a process for producing such fabrics.
Fabrics for clothes, especially those for uniforms and sporting garments usually must be excellent in stretchability and elongation in view of requirements as to the function and fitness.
Natural rubber has been long used for imparting stretchability to fabrics as is known. It is practice in recent years to use textured yarns of polyester, nylon or the like, or stretchable polyurethane elastic yarns to give stretchability to fabrics. It is also practice to use core-spun yarns comprising a core of such a textured yarn or polyurethane elastic yarn, and covered yarns obtained by winding filaments around a core. Further known is the chemical stretch process wherein cotton yarns are swollen by an alkali treatment, then subjected to an external force and thereby given a higher percentage of crimp. JP-A-150429/1995 proposes a fabric prepared from spun yarns which contain at least 70 wt. % of composite fibers comprising a copolymerized polyester and a polyester composed substantially of ethylene terephthalate units, the copolymerized polyester consisting primarily of ethylene terephthalate units which contain 2 to 7 mole % of 2,2-bis4-(2-hydroxyethoxy)phenyl!propane and 5 to 13 mole % of isophthalic acid as comonomers.
However, the use of natural rubber involves the problem that the rubber thread is thick and therefore gives an increased thickness to the fabric to result in limited use. The fabric obtained also has problems with respect to the durability and uneven stretchability due to the embrittlement of natural rubber.
The use of covered yarns encounters the problem that the covering operation increases the number of steps required to entail a higher cost and necessitates sophisticated techniques, for example, for tension control for weaving. Further the use of polyurethane entails the problem of embrittlement due to insufficient resistance to light and heat, etc.
The chemical stretch process is limited in elongation percentage and recovery percentage of elongation. The technique disclosed in the foregoing publication, i.e., JP-A-150429/1995, has the problem that the fabric is as low as up to 18% in elongation percentage and is not suited to prevalent use as a stretchable fabric.
The object of the present invention, which has been accomplished to overcome the foregoing problems, is to provide a fabric which is prepared from spun yarns and which is nevertheless excellent in stretchability and recovery from elongation, soft, plump, lightweight, elastic, and further capable of retaining its appearance and hand, and to provide a process for producing the fabric.